Various systems exist in the prior art for deriving accompaniment notes that enhance a melody in accordance with the selected harmony. Pending U.S. patent application Ser. No. 274,606 discloses a substantial improvement over prior art enhancement techniques that were, in general, hampered in the selection of accompaniment notes by limitation to a preselected musical compass below the melody note.
The art existing prior to the method and apparatus disclosed in the referenced patent application was thus unable to utilize advantageous non-chordal or non-scale tones when such tones were not explicitly sounded by the musician. Such a drawback becomes particularly critical when a musician of limited playing ability and/or dexterity seeks to sustain an accompanying chord with only a minimum number of tones. The invention described in the referenced application incorporates some significant aspects of musicianship into the automated instrument art by providing a system in which accompaniment notes are derived on the basis of the harmonic relationship between the melody and the selected chord. Briefly, the invention disclosed in that application achieves enhanced harmonization through the use of a plurality of listings of accompaniment notes in tables suitable for data processing. Data storage requirements are minimized through the utilization of a system of accompaniment note identification based upon musical transposition.
The aforementioned system and other harmony supplementation methods and apparatus of the prior art, while greatly enhancing the quality of the performed work, often betray their mechanical or electromechanical origins resulting in somewhat of a tradeoff between the improved harmonization achieved and a loss of realism due to the exactness with which the music is performed. This can sometimes result in a mechanical and unappealing musical texture.
The above-stated deficiency of prior art harmonization systems arises from the failure of such systems to recognize and incorporate the qualities of musicianship which lend character and realism to the performance of a skilled musician. For example, automatic harmonization systems conventionally sound the entire set of selected accompaniment notes at a single time. This generates an overall musical effect which differs from that one would expect from a skilled performer and/or orchestra. Skilled musicians add "style" to their performances by sounding accompaniment notes in various formats including sequences rather than simultaneous soundings of accompaniment notes. Further, a group of musicians, however skilled, will rarely, if ever, achieve the type of synchronization which commonly characterizes orchestrations performed by means of an electronic organ.
Attempts have been made in the prior art to enable an instrument, such as an electronic organ, to emulate techniques performed by a skilled musician to add realism and musicianship to the performance. The adaptation of various orchestrations by an electronic organ has been enhanced by prior art systems which in fact attempt to incorporate characteristics associated with the style of play of a selected instrument. Thus, the addition of the feature known as "automatic reiteration" to an organ incorporating banjo instrumentation overcomes, to some degree, the difficulty inherent in attempting to make an organ voiced to sound like a banjo (and played as an organ) make a convincing replica of a banjo being played. In automatic reiteration, all of the sounded notes, both melody and accompaniment, are repeatedly keyed.
Another technique which enables the performer to create a more realistic effect is the technique known in the organ industry as "delay vibrato". This technique is particularly appropriate in the playing of a violin where the performer holds a sustained note for a period of time, thereafter rocking his fingers to cause a vibrato effect. Electronic organs employing this effect commonly wait until the player sustains a note for a period of time before adding the electronic vibrato effect.
The foregoing systems which add realism to a performance by electronic organ, deal with each of the notes struck by the performer whether melody or fill note in a uniform manner. While the addition of such features aids a few of the common playing techniques, such treatment is simplistic in light of the broad range of musicianship which cannot thereby be adequately performed.
Very desirable musical effects result from the modification of the harmonizing notes in a manner independent of the melody note or any modification of the melody note. Three popular playing styles which rely upon the sequential soundings of harmonious accompaniment notes during the hold down period of the melody are known as "country piano", "strum" and "accordion" (or "tremolo").
The country piano style has evolved from the attempts of pianists to emulate the sounds of the fiddle and the mandolin, instruments whose strings are tuned in consecutive fifths. One technique according to country piano style is typified by the popular performer Floyd Cramer. This style is characterized by the addition to the melody of a single accompaniment note, as an appoggiatura, to a second accompaniment note chromatically adjacent to or separated by one or more chromatic tones. The melody note is not affected by the change of accompaniment notes. The appogiatura note is typically a short note while the sustained accompaniment note is held for the remainder of the melody. To avoid a monotonous musical texture, the skilled musician is selective in his use of this effect applying the technique in a sparing manner for maximum musical impact.
A strum effect may have one of a number of recognized forms in which different accompaniment notes are struck non-simultaneously and held. In the instance of a guitar-type strum, the accompaniment notes are generally sounded sequentially, either up or down in pitch, for preselected time periods before an additional accompaniment note is sounded.
A type of strum may be advantageously applied to orchestrations involving a number of instruments. In the playing of a musical piece, different performers, although seeking to synchronize with each other, will inevitably sound their instruments at differing points in time. Thus, an automatic harmonization technique wherein a plurality of accompaniment notes are sounded at slightly different points in time and held add a rich and realistic texture to the resulting music.
Tremolo emulates a technique often performed by accordion players. Such technique is accomplished by alternating two harmonious accompaniment notes as the melody note is sounded. This effect, which is done to break the monotony of sustained melody notes, often occurs as other accompaniment notes are held with the melody note.
Thus, highly advantageous musical effects may be realized by the implementation of automatic techniques and apparatus for effecting the sequential sounding of a plurality of harmonious accompaniment notes as a melody note is sounded. The present invention overcomes the disadvantages of the prior art and achieves the aforesaid advantageous result by providing, in a first aspect, a method for embellishing a melody selected by a performer in conjunction with a chord according to a predetermined musical style. The method, accomplished by the instrument itself, includes the steps of deriving a plurality of accompaniment notes, each of the notes being based upon the harmonic relationship of the melody to the chord and sounding the accompaniment notes in a preselected format to effect the predetermined musical style.
The invention provides, in an additional aspect, a method for embellishing a melody selected by a performer in conjunction with a chord, according to a predetermined musical style. The method, accomplished by the instrument itself, includes the step of deriving a plurality of accompaniment notes, each of such notes being based upon the harmonic relationship of the melody to the chord. More particularly, plural groups of accompaniment notes are provided, each of such accompaniment notes being associated with a chord and melody. The method further proceeds by the step of selecting at least one accompaniment note from each of the groups according to the melody and chord selected by the performer. The final step comprises sounding the accompaniment notes in a preselected format.
In a further aspect, the invention provides a method for deriving a plurality of signals in response to a melody note signal and a chord signal, the plurality of signals representing a corresponding plurality of accompaniment notes harmonically related to the melody note and to the chord and temporally related to effect a predetermined musical style. The method includes the step of storing a plurality of groups of listings of accompaniment notes. Each of the listings of a group corresponds to a chord type and provides at least one accompaniment note harmonically related to each melody note of the chromatic scale with respect to the chord type. The groups are arranged so that the listings of accompaniment notes for a particular musical chord type are related from group to group in accordance with the predetermined musical style. At least one preselected constant time value is provided and associated with at least one of the groups of listings. The root and type of the chord are then derived from the chord signal. The melody note is derived from the melody note signal. Listings are selected from the plurality of groups in accordance with the type of the chord. At least one accompaniment note is then located in each of the listings according to the chord root and melody note. Thereafter, a plurality of accompaniment note signals is sequentially generated, each of such signals being responsive to at least one accompaniment note of a selected listing, at least one of the signals having a duration corresponding to the constant value associated with the group from which it is derived.
In yet another aspect, there is provided apparatus for embellishing a melody selected by a performer in conjunction with a chord according to a predetermined musical style. Such apparatus includes means for deriving a plurality of accompaniment notes. There is also provided means for sounding the accompaniment notes in a preselected format.